The message – ‘Some people are gay. Get over it!’ – is displayed in giant, tabloid-style capital letters, on a bright red background.

The campaign, originally designed for schools, was developed in collaboration with 150 secondary school pupils and teachers for Stonewall.

They went on show last week.

“Sadly, the vandalism of a small number of the new Stonewall billboards is a reminder that homophobia still exists in our society and highlights the need to address the issue in schools and in our communities,” said Chris Gibbons, the gay charity’s senior education officer.

“However, we are encouraged by the overwhelmingly positive response we have received to this campaign.